The Canadian Food Inspection Agency (CFIA) has detected the presence of potato wart in a third field in Prince Edward Island.
The agency issued a statement Tuesday saying the fungus was detected in a field near two other farms where it was initially found in October 2021.
Last November, the federal government banned the export of seed potatoes from P.E.I., and the continental United States market has been closed to all Island potatoes ever since.
The federal agency says the latest find was not a surprise, considering it's common to detect potato wart in nearby fields during an investigation.
As well, the farm in question does not produce table stock potatoes and does not export to Puerto Rico.
When exports to Puerto Rico resumed last month, federal agriculture minister Marie-Claude Bibeau said she was optimistic shipments to the U.S. mainland could resume within a couple of weeks. But the minister later said a decision from the United States wasn't expected until the end of this month.
The fungal parasite spreads through the movement of infected potatoes, soil and equipment, and though it poses no threat to human health, it leaves potatoes disfigured and can decrease crop yields.
The P.E.I. Potato Board has said the Island's potato industry lost more than $25 million before exports to Puerto Rico resumed.
Last month, the federal and provincial governments announced funding to compensate farmers for the destruction of potatoes they couldn't sell.
To date, the agency has tested more than 3,500 samples from priority fields.
"The CFIA stands firm that, based on the science, the risk of transmitting potato wart from table stock potatoes and potatoes for processing remains negligible when appropriate risk mitigation measures are in place," the agency says on its website.
"The CFIA is continuing to work diligently to complete testing of all soil samples collected in its ongoing potato wart investigations."